David Michael Graham (born July 11, 1925) was an English actor. He voiced the Daleks in Doctor Who, Gordon Tracy, Brains, Aloysius Parker and Kyrano in Thunderbirds, and Grandpa Pig in Peppa Pig. Born in London on 11 July 1925. His sister had married a G.I. and had moved to the United States, and his uncle had run away there, so he became an actor after leaving his Orthodox Jewish household. He trained in New York City at the Neighbourhood Playhouse School of the Theatre with Sanford Meisner, following service in the Royal Air Force as a radar mechanic.

Graham's first breakout role before returning to England was Givola in The Resistible Rise of Arturo Ui, alongside Leonard Rossiter. While playing characters in the TV series Private Investigator in 1958, Graham met writer and producer Gerry Anderson, who was planning his first puppet productions. Graham mentioned to him that he could pull off accents well. His second voiceover role in Four Feather Falls was Grandpa Twink, whom he based on Walter Brennan. He subsequently voiced Dr. Beaker, Zarin and Mitch the Monkey in Supercar, Mat Matic and Lieutenant Ninety in Fireball XL5 and various guest characters in Stingray. Graham also played Johnny in Crossroads to Crime, a live-action film Anderson directed.

In 1963, he became the voice of the Daleks in Doctor Who, he voiced the Daleks in all four of their major First Doctor era appearances, as well as two 1960s feature films: Dr. Who and the Daleks and Daleks' Invasion Earth 2150 A.D. Graham also voiced the Mechonoids and played the onscreen role of Charlie in The Gunfighters. He returned to his role as the voice of the Daleks in 2023, when he recorded new lines for that year's official colourised recut of the 1963 serial The Daleks for the show's 60th anniversary.

In 1965, Graham became the voice of Gordon Tracy, Brains, Aloysius Parker and Kyrano in Thunderbirds, as well as its film sequels: Thunderbirds Are Go and Thunderbird 6. He did not believe Brains had a stutter, claiming that he was instead excitedly trying to find the words to explain his latest ideas. He based the voice of Parker on a waiter at the King's Arms pub in Cookham, and he and Ray Barrett shared roles as many of the guest villains. Although he was not highly paid for production, the many repeats earned him a lot more. Parker became Anderson's favourite voice.

Between 1975 and 1977, Graham was part of the Radio Drama Company. In 1979, he played Professor Kerensky in the Doctor Who story City of Death.

From 2015 to 2020, he reprised his role as Parker in Thunderbirds Are Go, a reboot of the original series.